19 
It is hardly necessary to point out that some of the samples in 
Tables III, IV, and V represent valuable material and others prac- 
tically worthless deposits. The maximum percentages of the fertil- 
izing constituents found in the 247 samples analyzed were as follows: 
Total nitrogen 13.04 per cent, nitrogen present as ammonia 3.60 per 
cent, nitrogen present as nitrate 4.60 per cent, total phosphoric acid 
41.58 per cent, water-soluble phosphoric acid 2.82 per cent, citrate- 
soluble phosphoric acid 28.66 per cent, water-soluble potash 4.18 per 
cent. The minimum figures found for the different constituents were 
practically zero. It will be noted that in many guanos most of the 
nitrogen is present as ammonia or nitrate. As was to be expected, 
the samples of best material came as a rule from caves in the drier 
parts of the island. 
Samples Nos. 886 to 890 from the small island of Caja de Muertos 
were doubtless formed by birds rather than bats. Many of the an- 
alyses reported in Tables II and IV are similar to those of leached 
bird guanos from Mona Island, as may be seen from the analyses in 
Table VI. 
Table VI. — Analyses of guano deposits from Mona Island. 
Labora- 
tory 
number. 
Total 
phos- 
phoric 
acid 
(P2O5). 
Citrate- 
soluble 
phos- 
phoric 
acid. 
Total 
nitrogen 
(N). 
1 
Calcium 
sulphate 
(CaSO*). 
Labora- 
tory 
number. 
Total 
phoric 
acid 
(P 2 o 5 ). 
Citrate- 
soluble 
phos- 
phoric 
acid. 
Total 
nitrogen 
(N). 
Calcium 
sulphate 
(CaS0 4 ). 
573 
574 
575 
576 
577 
578 
579 
Per cent. 
28.71 
26.36 
14.38 
4.68 
32.25 
45.41 
29.14 
35.52 
41.14 
26.20 
38.64 
27.06 
12.77 
3.21 
33.33 
3.06 
2.37 
2.10 
27.86 
42.23 
Per cent. 
13.85 
4.76 
2.26 
1.60 
12.96 
5.96 
2.63 
4.97 
1.88 
4.08 
4.56 
24.42 
4.79 
1.71 
1.73 

0.46 
.74 
1.06 
21.08 
Per cent. 
0.25 
.15 
.08 
.04 
.11 
.17 
.08 
.30 
.10 
.76 
.97 
.04 
.42 
.32 
.12 
.10 
.08 
.21 


Per cent. 
34.37 
7.46 
.43 
5.20 
22.29 
.82 
1.29 
23.67 
5.15 
34.16 
Trace. 
41. 45 
6.98 
6.57 
17.36 
Trace. 
Trace. 
3.79 
28.17 
3.80 
593 
594 
595 
596 
597 
598 
641 
642 
643 
644 
646 
647 
648 
649 
653 
654 
659 
664 
673 
750 
Per cent. 
18.00 
17.39 
37.52 
6.30 
1.87 
.85 
25.85 
37.25 
37.17 
30.54 
17.10 
9.50 
28.19 
21.39 
22.30 
31.70 
26.17 
21.62 
32.75 
27.68 
Per cent. 
3.37 
3.58 
23.10 
2.39 
.11 

5.57 
7.52 
2.45 
6.28 
3.29 
1.30 
3.46 
1.78 
Per cent. 

0.06 


.06 
.36 
Per cent. 
51.48 
55.93 
21.59 
64.29 
Trace. 
Trace. 
25.11 
580 
6.13 
581 
2.24 
582 
2.19 
583 
14.36 
584 
4.96 
585 
9.28 
586 
4.50 
587 
1.90 
.80 
2.72 
2.10 
6.08 
2.92 
Trace. 
588 
Trace. 
589 
590 
4.18 
591 
14.47 
592 

The samples from Mona Island represent materials from different 
caves, but by no means represent all the deposits on the island. 
VEGETATION TESTS WITH BAT GUANOS. 
GENERAL METHOD OF CONDUCTING TESTS. 
Many vegetation experiments in pots were conducted to compare 
the fertilizing efficiency of the nitrogen or phosphoric acid in bat 
guanos with the efficiency of the nitrogen or phosphoric acid in stand- 
ard commercial fertilizers. The results from some 2,300 pots are 
